Lipoprotein fraction analysis is a valuable tool in estimating the risk for coronary artery disease. The current procedure, however, requires multiple tests and has several manual steps. In order to reduce the complexity and cost of lipoprotein fraction analysis, we have developed a single-tube homogenous assay for measuring serum high-density lipoprotein (HDL) cholesterol, total cholesterol, and triglyceride. Low-density lipoprotein (LDL) cholesterol can then be calculated from these parameters using the Friedewald equation. The assay uses an anti-apoB antibody to block the reactivity of the reporter enzymes to LDL-cholesterol. The assay is performed in a sequential manner so that after the HDL-cholesterol is determined, a detergent is added to disrupt the antibody complex, which allows the subsequent measurement of total cholesterol. Next, the reporter enzymes for measuring total triglyceride are added. In the past year, we found that the assay was compatible with alternative procedures for blocking HDL, and the assay format also worked for first measuring LDL-C followed by total cholesterol. In the upcoming year, we plan to adapt the assay to an existing commercial assay for HDL-C and potentially transfer the technology to a diagnostic company for commercialization.